The present invention relates to a data processing device for providing data related to the types of services available at locations along a highway in response to operator input. In particular, this invention relates to a data processing device which stores data related to the types of services available at locations along a highway in a compressed form.
To determine what types of services, such as food or gas, are available at locations along a highway, one has to either depend upon billboards along the highway or leave the highway in order to locate a specific type of service. It is not unusual that a motorist may leave the highway in an attempt to locate a particular gas station or food store only to find out later that the particular station or store was only a few miles down the highway. Additionally, maps are used to locate various types of services. However, the maps may be out of date or at best contain only limited information concerning the types of services available along the highway.
In order to solve this problem, various devices have been developed which provide information relating to services available along a highway. However, these devices require different interchangeable ROM (read only memory) packs or modules be used for either different highways or different states. Since these devices are organized by highways or states, it is difficult to determine the nearest service to a border area or major intersection without frequently changing modules. This is because such devices are unable to identify services across borders. It would be advantageous to have a device which did not require separate modules to store information and changing modules when information concerning a different highway is required or when a motorist reaches a state border.